Processes for the preparation of cyclopolymethylenic ketones



Patented Oct. 20, 1953 UNITED 2,656,390

ritooiisSEs FQK'IHE PREPARATION or CYCLOPOLYMETHYLENIC KETONES MaxStall, Geneva, Switzerland, assigno'r to Firnieliich & 00., successeursde la Societe Anonyme M. Nae'f '& Cie., Geneva, Switzerland, a;corporation of Switzerland departing, Application September 27, 1948,Serial "No. 51,481; In Switzerland October '1,

9 claims. 7 l The present in'vention'relates to a process for thepreparation of cyclopolymethylenic ketones, alkylated or not, havingfrom to 18- members in the ring, Whose formula is wherein R, representsa chain of from 9 to 1'7 groups -CH2 one or severalci which can bealkylated, for instance methylated.

This proces's consists subjecting to a partial reduction al,-2'-"cyclopo1ymethylenic ketol, alkylated or not and havingin its ringthe same number of members as that of the desired ketone.

The invention is based on the unexpected fact that in the1,2-cyclanolones (Formula II) hav-- ing from 10 to 18 members in thering (in the Formulae I, II, and III -r=18 to 16) thehydroxyl group can,for the most part be reduced to a QH2 group before the ketone groupitself is reduced to a-CI-I group, which allows a direct reduction orthe 1,2-cycia'iit1tnes to eyelancnes (Formula III). This partialreduction, which the characteristic of the process of the invention, andwhich may be carried out according to known -methods, has the advantageof being applicable riot'only to pure 1,2-cyclanclones as those obtainedaccording to the process, described in the U. S. patent application No.

714,650 of December 6, 1946, ew U. s. Patent No. 2,529,825, but also toimpure 1,2'-cyclanolones, such as those obtained according to theprocess of the U. S. P atent No 2,228,2 68 which arse contain isomericproducts or "cyclopolyrnethylenic-L2-diketones (Formula I). Thesediketones are first "reduced to cyclanolone's, so

that the 'cyclanolones cohtaining' such diketcnes 'give yields ofpcly'methylenic 'ketcnes which reach to of the yields obtained with purecyclanolone's.

y The reduction of, t he cyclanolones into eyelanones 'being'a partialreduction, itis "or course necessary to maintain the conditions ofretina.

to have it prbdii butasmairtiuantitytrttuane' besides the cyelano'ri'e,This adjustment is to :be obtained either through an adjustment in thetemperature, or through an adjustment in' the concentration of thehydrochloric acid used jointly with zinc, or yet in the choice of thesolvents in which the reduction is carried out, or of the dilutionof thereagents of the catalysts (salts of lead) used, etc, v

Inasmuch as the cyclanolones; (Formula II}, or their admixtionwith-cyclanediones (Formula I), have become easily accessible, theirreduction represents an important industrial progress for thepreparation of cyclopolym ethylenic ketones.

A few concrete examples-are given below to illustrate the process." Butthey do not exhaust the metl-iodsof -reduction-nor the workingconditions which can be used, as the adjustment-of ducted through a tubefilled with purified asbestos carrying 40gr. of zinc dust heated etc345- 355 C. The velocity of the distillation is such that in one houranl ahalf 7 gr. of product are distilled. The distillate partlycrystallised, yields 5.5 gr. or s'eini-eartaz'ofie "of the P. lf78-'180.The yieldin cycloheiiadecanon'e is roughly 47% of the theoretic yield.

Ea'zdmple 2 4 gr. of cyclchexadecanolcne lm, purified sby distillation,are dissolved in 180 -cm; tot crude ethyl-alcohol. After adding thereto:80 gr. of zinc dust, the solution-'isr'heated tc boilingmoint and a,rapid rgaseous hydrochloric acid current is introduced therein (about 1:gr. I-IC'l per until the zinc is almost-entirely "consumed, whichrequires roughly 8 hours. ,After dilution :with water and extractionwith other, "etc- 3.85 gr. aof neutral parts -.are obtained, 3. 15 gr.of which distil under a gpressiire of 0.05 mm. between (l10)"-120-find;-:yie1di"3-.1 gr. of :semic'arbazone melting "at 181- 182 The yieldin cyclohexadecanone -is 62% 0f the theoretic yield.

mantle s 101 8 gr. 6f bybldiiefihfilfifl lfi, distill 0m, are dissolvedin 25 grammes of searched and poured on 25 grammes of zinc wool. Afteradding 25 grammes of concentrated hydrochloric acid, the whole is heatedon an oil bath at 100. 25 grammes of concentrated hydrochloric acid areadded every half hour. 100 grammes of that acid are used altogether.After the usual treatment, the reaction product is treated with asolution of semicarbazide hydrochloride. After recrystallization, 95 gr.of semicarbazone of the cyclodecanone are obtained (71% of the theoreticyield) melting at 203-205. 3.712 mgr. of substance yielded B.464 mgr.CO2 and 3.304 mgr. H20.

CuHzrONs I Calculated 1- C, 62.52; H, 10.02%. Found C, 62.37; H, 9.96%.

A mechanical stirring is favourable to that kind of reduction. The yieldmay then reach 190% of the theoretic yield, especially if the so-.lution of the initial product is drop ed slowly in the acetic acid.

Example 4 *8 gr. of cyclopentadecanolone-1,2, distilled once, aredissolved in 16-0 cm. of dioxane. 40 gr. of zinc wool are added to thesolution and the latter is heated to boiling point introducing therein agaseous hydrochloric acid current at a velocity of 15 gr. per hour. Asthe zinc dissolves, the velocity of the gaseous current is lessened upto 3 gr. per hour. The reduction lasts from 2% hours to 3 hours. Thedioxane and the zinc are eliminated, then the reaction product dissolvedin ether is washed with sodium carbonate and water. Roughly 16 gr. ofzinc are recovered. The product is distilled under 0.04 mm. of pressureand a fraction of 6.55 gr. is obtained which 'distils between 111 and153 C. This fraction is treated in the cold with light petroleum etherand thus 0.26 gr. of insoluble products are eliminated. The solubleproduct is converted into semicarbazone. 6.5 gr. are obtained therefrom,melting at 182-183". If the latter is mixed With semicarbazone ofexaltone melting at 187, the r M. P. of the latter does not undergo anydepression.

Yield-70% of the theoretic yield. 0.7 gr. of product does not yield anysemicarbazone.

Example gr. of cyclopentadecanol-2-one-1, distilled once, are dissolvedin 30 cm. of ethyl-alcohol. To this mixture are added in the cold 10 cm.of concentrated aqueous hydrochloric acid (40%) and 2 gr. ofzinc-filings. The whole is heated to boiling point. When the zinc isalmost consumed, 2 gr. of fresh zinc and 5 cm. of hydrochloric acid areagain added, so that the concentration of the acid never exceeds 8%.After adding thus 22 gr. of zinc (17.1 gr. of which are consumed) and 55cm? of hydrochloric acid, the reaction product is extracted with ether.9.68 gr. of neutral parts are obtained, 7.71 of which distil under 0.07mm. between 117-170 C. (6.43 gr. between 117-127 C.) yielding 7.73 gr.of semicarbazone of the M. P. 182-185 C. The yield in cyclopentadecanone(exaltone) is 66% of the theoretic yield.

If for the reductions described under Examples 3 to 5 cyclanolone isused in larger dilution, the

- quantity of the residues lessens and the yields in- What I claim is:

1. A process for the preparation of cyclopolymethylenic lqetones, havingten to 18 carbon atoms in the ring, consisting in reducing the hydroxygroup of a 1-2 cyclopolymethylenic ketcl, having in the ring the samenumber of carbon atoms as that of the desired ketone, to a CH2 group byreducing the same with a reduction agent comprising metallic zinc insuch manner that only minor quantities of the keto group contained inthe molecule are reduced.

2. A process as defined in claim 1 wherein the starting material 1-2cyclopolymethylenic ketol contains at least one alkyl group as asubstituent in the ring,

3. A process according to claim 1, consisting in using as startingmaterial 1,2-cyclopolymethylenic ketols in their crude state.

4. A process according to claim 1, wherein the starting material is1,2-cyclopolymethylenic ketols containing 1,2-cyclopolymethylenicdiketones as impurity.

5. A process according to claim 1, consisting in efiecting the partialreduction with metallic zinc and hydrochloric acid.

6. A process according to claim 1, consisting in efiecting the partialreduction with metallic zinc and aqueous hydrochloric acid in a liquidmedium containing an organic solvent.

7. A process according to claim 1, consisting in efiecting the partialreduction with metallic zinc and gaseous hydrochloric acid in an organicsolvent.

8. A process according to claim 1, consisting in effecting the partialreduction by passing vapours of ketol over zinc dust heated between 300and 360 C. and in a high vacuum.

9. A process according to claim 1, consisting in efiecting the partialreduction with the help of zinc and hydrochloric acid the concentrationof which is kept, during the reduction, to approximately 8% of thereaction mixture.

MAX STOLL.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,702,852 Ruzicka Feb. 19, 1929 2,228,268 Hansley Jan. 14,1941 OTHER REFERENCES Wallach: Annalen, vol. 414, pages 367-371 (1917).

Ruzicka et al.: Helv. Chim. Acta., vol. 11, pages 496-512, (1928). Copyin Dept. of Agriculture Library, Chemical Abstracts, vol. 22, C01. 2928(1928).

Ruzicka et al.: Helv. Chim. Acta., vol. 11, pages 670-686 (1928). Copyin Dept of Agriculture Library, Chemical Abstracts, vol. 22, Cols. 4482-4483 (1928).

Ruzicka et al.: Helv. Chim. Acta., vol. 13. pages 1152-1185 (1930). Copyin Dept. of Agriculture Library, Chemical Abstracts, vol. 25, C01. 922(1931).

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Shoppee: J. Chem. Soc., 1928, pages 1662-70.

1. A PROCESS FOR THE PREPARING OF CYCLOPOLYMETHYLENIC KETONES, HAVINGTEN TO 18 CARBON ATOMS IN THE RING, CONSISTING IN REDUCING THE HYDROXYGROUP OF A 1-2 CYCLOPOLYMETHYLENIC KETOL, HAVING IN THE RING THE SAMENUMBER OF CARBON ATOMS AS THAT OF THE DESIRED KETONE, TO A CH2, GROUP BYREDUCING THE SAME WITH A REDUCTION AGENT COMPRISING METALLIC ZINC INSUCH MANNER THAT ONLY MINOR QUANTITIES OF THE KETO GROUP CONTAINED INTHE MOLECULE ARE REDUCED.